A slow and regular breathing activity is considered to be beneficial for relaxation. To support the breathing process, several different breath pacing devices are known to provide output signals that correspond to a desired regular breathing rhythm and can easily be perceived by a user.
US-20070114206 discloses a breath pacing device comprising respiration sensors for producing a breath condition signal that is displayed to a user as a feedback to his actual respiration. On the reception of this signal, the user can adapt his respiration practice for learning purposes. In this case the sensors are integrated into an article of clothing like a shirt, for example. This system is not suitable where relaxation is desired.
A pacing signal can also be, for example, a light that changes its intensity, color or shape periodically according to the desired respiration cycles. In one possible application, breath pacers can be used in bed by a person to reduce sleep onset latency. These breath pacers project a light spot of slowly varying size on the ceiling of the bedroom. A further example for a pacing signal is an audio or video signal.
One problem related to the operation and control of such devices lies in the necessity to find a suitable operation mode at the beginning of a pacing sequence or, in other words, a “starting point” at which the system begins to operate. The system works most efficient when the output signal is adapted to the present respiration characteristics of the user. This stands especially for the respiration rate, i.e., the frequency of the respiration cycle, and other time characteristics within each respiration cycle (e.g. inhalation time, exhalation time, pause times) but also for the amplitude. An output signal synchronized to the present user's breathing frequency helps the user to adapt to the pacing rhythm of the apparatus. However, at present there is no efficient and practical way to adapt the output signal to the user's respiration rate automatically.